I recently replaced a 20+ year boiler with a Weil-Mclain GV90+. My installer used the existing setup where there was a circulating pump on the return that was continuously circulating into the boiler. The boiler is having problems heating some of the radiators on the 2nd and 3rd floors so I decided to read the boiler manual:
and in the circulators section i found the following paragraphs:
"Never install another pump in series with the GV90+ boiler. Forced flow can cause improper operation of the boiler controls. Substantial property damage could result.
Failure to comply could result in unreliable performance and nuisance shutdowns from insufficient flow."
It looks like the the boiler was installed incorrectly? Does the pump need to be removed or relocated?